CN101428333A - High-temperature metal casting sand core - Google Patents

Abstract

The invention discloses a high-temperature metal casting sand core, the main material adopts pyrophyllite, and the solvent adopts silica sol, which are mixed to form a sand core. After both the pyrophyllite and the silica sol are combined, adhesion and hardening are generated in a short time so as to form the sand core with a certain bearing strength, and both the pyrophyllite and the silica sol have the characteristic of high temperature resistance at the same time; after high-temperature metal casting forming, the sand core has the characteristic of frangibility so that the mold core of special shape products after molding is conveniently cleared, compared with the clearance of the hard mold core such as the ceramics formed by adopting the special sand such as the zircon sand, the chromite sand, the emery and the like, the clearance of the sand core is more convenient and rapid; therefore, the processing efficiency of the high-temperature metal casting process can be greatly enhanced, and the manufacturing cost for clearance of the mold core is effectively reduced.

Description

High-temperature metal casting sand core

Technical field

The relevant a kind of casting sand core of the present invention is meant a kind of high-temperature metal casting sand core especially.

Background technology

Casting is Metal Melting to be smelt meet necessarily required liquid and water in casting mold, obtains the technical process of the foundry goods of reservation shape, size and performance through cooled and solidified, after leveling processing.The casting blank is shaped because of being close to, and has reduced cost and has reduced the time to a certain extent and reach the purpose of exempting from machining or a small amount of processing.Casting is one of fundamental technology of modern mechanical process industry.

Cast employed core and be mostly to be mixed by a certain percentage by roughing sand (mountain sand or river sand), clay and water, its medium clay soil is about 9%, and water is about 6%, and all the other are roughing sand.Sometimes also add on a small quantity as the performance of additives such as coal dust, vegetable oil, wood chip with raising molding sand and core sand.The basic raw material of making sand mold is casting model powder and moulding sand binder.The most frequently used casting model powder is a siliceous sand.When can not satisfying instructions for use, the high-temperature behavior of silica sand then uses special sand such as zircon sand, chromite sand, emergy.

At present at the higher metal of some temperature in casting process, because temperature is too high, as stainless steel reach can realize more than 1000 degrees centigrade the casting, use as special sand such as zircon sand, chromite sand, emergies and make core, be subjected to high temperature action, the degree of this molding sand sclerosis is also higher, as forms pottery etc., so for the stainless steel product of some special shapes, clearing up for the fragmentation of core then is the comparatively problem of difficulty of industry.

Summary of the invention

The purpose of this invention is to provide and a kind ofly have certain high-temperature behavior, be convenient to the high-temperature metal casting sand core of fragmentation cleaning again to satisfy the casting of high-temperature metal.

Be practical above-mentioned purpose, solution of the present invention is: a kind of high-temperature metal casting sand core, its major ingredient are pyrophyllite, and solvent is a Ludox, and the two mixes the formation core.

Described major ingredient is mixed by alumina cement and the 80%-100% pyrophyllite of 0-20%, and described component by weight.

Described major ingredient is mixed by heavy burned magnesium oxide and the 80%-100% pyrophyllite of 0-20%, and described component by weight.

The prodan that also adds the 1%-5% that accounts for major ingredient weight in the described major ingredient mixes.

Add sodium metasilicate in the Ludox of described solvent, it accounts for the 2%-6% of Ludox weight.

Described core is to be mixed with the solvent that is equivalent to major ingredient 70% weight by major ingredient, and the two carries out 5 seconds to 30 seconds stirring fast at normal temperatures, reverse mould afterwards, wait normal temperature gluing in 10 minutes to 60 minutes after, carry out the demoulding, finish core after the drying.

After adopting such scheme, because the present invention adopts pyrophyllite as the core major ingredient, utilize Ludox as solvent, the two is in conjunction with producing bonding sclerosis in the short time of back, has the core of certain support strength with formation, and simultaneously, the two all has resistant to elevated temperatures characteristics; Behind the high-temperature metal casting, this core has frangible characteristics, so be convenient to the core cleaning after the special shape products moulding, comparing special sand such as adopting zircon sand, chromite sand, emergy forms as the cleaning of hard cores such as pottery convenient and quick, thereby can improve the working (machining) efficiency of high-temperature metal casting processing greatly, effectively reduce the production cost of core cleaning.

The specific embodiment

High-temperature metal casting sand core of the present invention is to be mixed by major ingredient pyrophyllite and solvent Ludox.

Because the major ingredient pyrophyllite is a kind of of clay mineral, belonging to crystalline texture is the stratiform hydrosilicate mineral of 2:1 type, and chemical structural formula is AL2[SI4O10] (OH) 2, theoretical chemistry consists of AL2O3 28.3%, and SIO2 66.7%, and H2O 5%.Pyrophyllite is the clay mineral that the low temperature hot liquid alteration forms, and it is Japanese to belong to monocline, and the crystal structure height is unordered; It has the quality exquisiteness, and hardness is low, density 2.65-2.90/CM, and refractoriness is greater than 1700 degrees centigrade, and insulation, thermal insulation are good, stable chemical performance, having only could be by characteristics such as sulfuric acid decomposition under the high temperature;

And Ludox belongs to colloidal solution, and odorless is nontoxic, and its colloidal particle fine (10-20MM) has sizable specific area, and viscosity is lower, and the porous place of water can both be permeated, therefore and dispersiveness and permeability during other material mixing all very good; When the water evaporates of Ludox, colloidal particle forms the silica combination securely attached to body surface between particle, be good adhesive, and high temperature resistant 1500-1600 degree centigrade.

Therefore the two in conjunction with after can satisfy the casting requirement of high-temperature metal core fully, the core after metal casting is frangible, thereby reaches the function of being convenient to clear up, and with adaptive special shape high-temperature metal cast article, enhances productivity.

For increasing the fragility of this high-temperature metal casting sand core, its major ingredient is that alumina cement and the 80%-100% pyrophyllite of 0-20% mixes; Or the heavy burned magnesium oxide of 0-20% and 80%-100% pyrophyllite mix, and described each component is by weight.High-temperature cement all has the short and certain high temperature resistant characteristics of firm time with heavy burned magnesium oxide, at high temperature also can keep 70% more than of original intensity.Add the intensity that can effectively improve core in the major ingredient.

For further improving the bulkiness of core, so that cleaning, the prodan that adds the 1%-50% that accounts for major ingredient weight in major ingredient mixes.

Add sodium metasilicate in the Ludox of solvent in addition, it accounts for the 2%-6% of Ludox weight, and the two mixes, and its objective is to adjust solvent and the mixed setting rate of major ingredient.

Core of the present invention is that major ingredient is mixed with the solvent that is equivalent to major ingredient 70% weight when concrete the making, and the two carries out 5 seconds to 30 seconds stirring fast at normal temperatures, reverse mould afterwards, after normal temperature gluing in 10 minutes to 60 minutes, carry out the demoulding, finish core after the drying.

Then carry out the high-temperature metal casting: fixedly--------sintering--is cast--cooling---sand removal to core in dewaxing to be stained with slurry to penetrate wax.

Claims (6)

1, a kind of high-temperature metal casting sand core, its major ingredient are pyrophyllite, and solvent is a Ludox, and the two mixes the formation core.

2, high-temperature metal casting sand core as claimed in claim 1 is characterized in that: this major ingredient is mixed by alumina cement and the 80%-100% pyrophyllite of 0-20%, and described component by weight.

3, high-temperature metal casting sand core as claimed in claim 1 is characterized in that: major ingredient is mixed by heavy burned magnesium oxide and the 80%-100% pyrophyllite of 0-20%, and described component by weight.

4, as claim 1,2 or 3 described high-temperature metal casting sand cores, it is characterized in that: the prodan that also adds the 1%-5% that accounts for major ingredient weight in the major ingredient mixes.

5, high-temperature metal casting sand core as claimed in claim 1 is characterized in that: add sodium metasilicate in the Ludox of solvent, it accounts for the 2%-6% of Ludox weight.

6, high-temperature metal casting sand core as claimed in claim 1, it is characterized in that: core is to be mixed with the solvent that is equivalent to major ingredient 70% weight by major ingredient, the two carries out 5 seconds to 30 seconds stirring fast at normal temperatures, reverse mould afterwards, after normal temperature gluing in 10 minutes to 60 minutes, carry out the demoulding, finish core after the drying.